Panel/Button missing- Unsure of what it was. Manual does not call it out.

Hey all,
I had my car in to get fine tuned before a big trip and it came back without a
button cover (for lack of word) on it in the interior. I'm unsure what it is called
as it isn't called out in the Owners Manual nor did it ever have any wording
on it. The place I took it to doesn't know where the panel would be nor could
give me any info.

I've circled the piece missing in the image. I would honestly leave it be if it
wasn't for the fact that it is extremely white and eye catching now. I am
looking to replace it myself once I can identify what it was that was there.